I'm a recent Remora customer.
When it comes to carry guns and gear, I'm kind of like Steve Rodgers in the Captain America comics...I was pretty current until about twenty years ago, went into hibernation and just recently thawed out.
The idea of a no clip/loop sticky IWB holster struck me as pretty fantastic, or a gimmicky rip-off. Real holsters have attachment points and are made from dead critters. Why not just carry Mexican with the gun in an old, sticky sock? Makes as much sense. Maybe it works with those new helium filled alloy and nylon micropistols, but not with my old fashioned anvil weight shooting irons.
After reading all the positive reviews, curiosity and my inner cheapskate got the better of me, and I ordered a Remora 12C with the reinforced top and sweat shield for a Combat Commander, with the idea of sneaking a BHP in it, too. After all, if it's really that good and it's that inexpensive, what the heck? If it sucks, I can always figure out a way to stuff it between the seat and the console of my car.
Turns out the Remora works really well for me, and with a pistol that weighs 43 ounces loaded. Your Glock 19 should be about 13 ounces lighter.
With a bigger pistol, I'd not want to count myself in with the "Remora works for me with just gym shorts and sweatpants" crowd. I wear a belt, but it works with a regular ol' dress belt just fine.
Honestly, even with the belt, in the back of my mind there's this "Oh, crap, just wait 'till that thing slides down your pants while you're reaching for the salsa in aisle three" thing whispering in my ear, but so far, it's all psychological. All the actual evidence points solidly to the contrary-that thing stays put where I put it, period.
The grippiness (it's not really sticky) of the Remora against the body or t-shirt does seem to help spread the load, so the the pistol carries lighter, if that makes any sense.
So far, I'm a fan, and think your Glock 19 will be a comparative piece of cake for a Remora.